A "LUT", or "lookup table", is an array of preselected values used in movie color-correction to map colors from the original input footage to the desired colors in the final output. Color correction is performed by looking up input colors and assigning them new RGB values based on the data in the table.
A lookup table that treats each of the red, green, and blue channels separately is a "1D LUT", which cannot be used to correct saturation or hue. Such corrections require a "3D LUT", in which each combined RGB value maps to a single combined value in the table.
Designed to take full advantage of sensor dynamic range, Nikon's unique "N-Log" logarithmic gamma curve offers excellent balance between highlights and shadows and is optimized for 10-bit movie recording. Information on filming N-Log footage can be found in Technical Guide (N-Log Recording Edition) handbooks available from the Nikon Download Center.
Designed specifically for the purpose, Nikon's N-Log 3D LUT greatly makes color grading N-Log footage a snap. Although the N-Log gamma curve captures a wide range of tones, the raw footage will seem to lack contrast and must be color graded for display on Rec. 709 monitors.
To color grade N-Log footage using the N-Log 3D LUT, you will need third-party movie editing software. This guide shows how to apply the N-Log 3D LUT using Blackmagic Design's DaVinci Resolve 15.